MHT Series Hydraulic Rotary Gear Oil Pump Replacement | MHT50 MHT90 MHT250

The MHT Series Heavy-Duty High-Pressure Hydraulic Rotary Gear Oil Pumps by Chengyuan Hydraulic—encompassing our full global framework sizes MHT24, MHT32, MHT50, MHT70, MHT90, MHT150, MHT190, and MHT250—are premium industrial-grade fluid components engineered for 100% direct drop-in interchangeability with leading international heavy-cast-iron gear pump lines. Manufactured strictly to global industrial footprint and layout constraints, these rotary gear pumps perfectly mirror original mounting flanges, input shaft specs, and SAE/metric connection threads. This enables immediate, seamless replacement on the production floor without requiring structural layout remodeling or pipe adaptation.

Engineered as the dynamic horsepower nucleus for fluids containing high contamination risk and enduring relentless mechanical stress, the MHT series incorporates a high-tensile monoblock cast iron housing. This architecture handles continuous operating pressures up to 250 bar while proving completely impervious to thermal expansion or body distortion in high-viscosity mediums. At Chengyuan, every individual MHT gear pump clears our 100% dynamic simulation testing schedule before logistics dispatch. We record volumetric efficiency maps and internal temperature-rise curves under true heavy-duty pressure spikes, guaranteeing that every field delivery achieves OEM-equivalent uptime and flawless industrial reliability.

Technical Specifications

• Product Series: MHT Series High-Pressure External Rotary Gear Oil Pump

• Housing Structural Material: Premium Compacted Graphite Iron (CGI) / High-Grade Cast Iron

• Specific Model Engineering Parameters:

  • MHT24: Geometrical Displacement 24.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 250 bar (25 MPa); Maximum Peak Pressure 280 bar; Operating Speed Spectrum 500 – 3000 rpm; Approximate Net Weight 9.5 kg.

  • MHT32: Geometrical Displacement 32.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 250 bar (25 MPa); Maximum Peak Pressure 280 bar; Operating Speed Spectrum 500 – 3000 rpm; Approximate Net Weight 10.2 kg.

  • MHT50: Geometrical Displacement 50.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 250 bar (25 MPa); Maximum Peak Pressure 275 bar; Operating Speed Spectrum 400 – 2500 rpm; Approximate Net Weight 12.8 kg.

  • MHT70: Geometrical Displacement 70.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 240 bar (24 MPa); Maximum Peak Pressure 265 bar; Operating Speed Spectrum 400 – 2500 rpm; Approximate Net Weight 14.5 kg.

  • MHT90: Geometrical Displacement 90.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 230 bar (23 MPa); Maximum Peak Pressure 250 bar; Operating Speed Spectrum 400 – 2200 rpm; Approximate Net Weight 16.2 kg.

  • MHT150: Geometrical Displacement 150.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 200 bar (20 MPa); Maximum Peak Pressure 220 bar; Operating Speed Spectrum 300 – 1800 rpm; Approximate Net Weight 28.0 kg.

  • MHT190: Geometrical Displacement 190.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 180 bar (18 MPa); Maximum Peak Pressure 200 bar; Operating Speed Spectrum 300 – 1800 rpm; Approximate Net Weight 32.5 kg.

  • MHT250: Geometrical Displacement 250.0 cc/rev ($cm^3/rev$); Nominal Continuous Pressure 160 bar (16 MPa); Maximum Peak Pressure 180 bar; Operating Speed Spectrum 300 – 1500 rpm; Approximate Net Weight 41.0 kg.

• Recommended Hydraulic Fluid Matrix: Mineral-based oils, high-viscosity lubricants, or anti-wear industrial fluids (Viscosity bandwidth: 20 to 400 $mm^2/s$).

• Fluid Working Temperature Range: -20°C to +90°C.

Key Technical Advantages

• Monoblock High-Rigidity Cast Iron Envelope: Eradicating the common pitfalls of aluminum-body substitutes that suffer bore-scoring under structural strain, the MHT series utilizes premium solid compacted graphite iron. This structural configuration delivers superior anti-fatigue performance and exceptional mechanical stiffness. Under continuous 250 bar loading, internal clearances remain strictly intact, preventing geometric internal bypass oil slippage.

• Tri-Stage Hydraulic Floating Axial Compensation: The pump interior integrates high-precision dual floating thrust side-plates. By directing a metered feedback channel of pressurized fluid behind the plate assemblies, specialized dynamic-pressure zones push the plates perfectly parallel to the gear faces as system pressures escalate. This self-compensating mechanism preserves volumetric efficiency at a steady 96% across large sizes like MHT150 and MHT250.

• Heavy-Duty High-Capacity DU Journal Bushings: Abandoning traditional, damage-prone internal needle bearings, our MHT series is fitted with high-load self-lubricating DU composite bushings. Providing over 40% greater surface load concentration area, they masterfully absorb the severe radial unbalanced hydraulic stresses generated by high torque while demonstrating superior particle-embedment tolerance to combat uneven wearing.

• Precision CNC Micro-Profiled Involute Gearsets: The drive and idler gear-shafts are forged from premium high-alloy steel, case-hardened via precise carburizing, and ground on state-of-the-art CNC grinding centers. Micro-machined fluid-dynamic profile modifications effectively mitigate transient peak pressure traps between the interlocking teeth, dampening fluid pulsation and dropping audible noise by 5-8 dB(A).

Application Areas

Thanks to their vast range of displacement options and resilient cast-iron housings, MHT series pumps excel in highly contaminated, abrasive environments across key sectors:

• Industrial Metallurgy & Primary Steel Plants: Blast furnace raw material handling charging systems, heavy mill roll lubrication circuits, offline oil-cooling filtration power units, and heavy industrial scrap shears.

• Heavy Mining & Subsurface Substructure: Coal mine underground hydraulic manifold wash pumps, open-pit ore crusher hydrostatic controls, and heavy mining vehicle dump actuation loops.

• Marine & Offshore Deck Hardware: Mooring anchor winch fluid recirculation loops, steering gear power modules, and auxiliary charge feed systems for massive marine thruster configurations.

• Heavy Environmental & Special Utility Vehicles: Primary packing cylinder drive loops for waste refuse compaction trucks and multi-axle hydrostatic auxiliary steering systems for heavy modular transporters (frequently utilizing MHT50/70/90).

Expert Maintenance Tips

• Mandatory Manual Intake Pre-Priming: Although external gear geometries exhibit inherent self-priming capabilities, large-displacement frames (such as MHT150, MHT190, and MHT250) isolate large internal volumes. Prior to coupling electrical power for the first time, manually pre-fill the pump intake port with micro-filtered oil and rotate the shaft several turns by hand. Never spin the pump dry with empty internal chambers.

• Avert Suction Line Cavitation Failures: High-displacement pumps like the MHT250 generate massive fluid demand at peak speeds. Ensure the suction piping is correctly sized (generous diameter) and kept as short as structurally possible. Avoid installing restrictive fine-mesh inline filters on the intake line. The absolute inlet vacuum level must never drop past -0.3 bar, or cavitation implosions will erode gear surfaces.

• Rigid Loop Fluid Hygiene Management: While heavy cast-iron structures offer greater resilience against particle pollution than piston-type configurations, maintaining a pristine load-bearing fluid film requires clean oil. Maintain system cleanliness metrics to meet ISO 4406 21/19/16 (NAS Class 10) parameters, and ensure that return or kidney-loop paths integrate magnetic core filtration elements rated at $\le 25 \mu m$.